The present invention relates to wireless communication, more particularly to routing of nodes in wireless ad hoc networks.
The so-called “ad hoc routing protocol” is a common genre of wireless routing protocols. A wireless ad hoc network is a kind of wireless network in which nodes are deployed in an “ad hoc” fashion. The nodes of a “multi-hop” wireless communication network are managed by an ad hoc routing protocol. Generally speaking, there are three categories of ad hoc wireless protocols for routing the nodes, viz., “table-driven” protocol, “on-demand” protocol, and “hybrid” protocol. Important aspects of wireless ad hoc networking include latency, chipset, and efficiency.
The “routing” of an attempted wireless communication from point “A” to point “B” is conventionally understood to involve the directing of an electromagnetic signal (e.g., radio waves) from node to node, starting at a source node (at or near point “A”) and ending at a destination node (at or near point “B”). The signal may be routed directly from the source node to the destination node, or may be routed indirectly, i.e., with one or more signal-connecting nodes between the source node and the destination node. Conventional algorithms for “routing discovery” (discovering routes) are usually based on combinations of two criteria, viz., the shortest route and the highest link quality.
Though frequently effective, ad hoc routing protocols based on shortest route and highest link quality may prove unsatisfactory for some applications. In particular, a wireless communication network may be of such a critical nature that failures to communicate simply cannot be tolerated. For critical control functions, the provision of successful wireless communication without network latency is a vital capability. Wireless data communication for mission-essential tasks—for example, those onboard naval ships—should not be beset with difficulties akin to those prompting frustrated verbalizations by wireless voice communicators (e.g., cell phone users) such as “Can you hear me now?” or “Just wait . . . . Let me try to find a way to get back to you!”
The U.S. Navy is considering initiatives for reducing manning of future combat ships. Reduction of shipboard personnel will require greater automation of systems, not only for operation purposes but also for survivability purposes, particularly in terms of damage control. With regard to survivability, wireless communication can provide the capability of reconfiguring critical control system information for mission essential tasks, subsequent to damage of the primary wired system. A wireless sensor and control network (synonymously referred to herein as a “wireless sensor network”) is a kind of network having a (usually, large) number of nodes. As envisioned by the U.S. Navy for damage control objectives, each node of a wireless sensor network will be equipped with various devices embedded therein, including a processor, one or more sensors, and a radio.